The present invention relates to improvements in feeding devices for high speed nut formers such as disclosed in co-pending application no. 644,942 filed Dec. 29, 1975 by the present inventor, now U.S. Pat. No. 4,014,058.
As stated in said co-pending application, the major defects of conventional devices for the transfer of blanks to various die stations is that, firstly, it is necessary for the cutting device to transfer the cut blank from a cutting die to the first die station, generally impeding the speed of the cutting operation. Secondly, blanks are transferred between die stations by transfer fingers or arms along an arcuate path away from and back to the face of the die assembly so that the ram carrying the punch assembly must return along this same arched path to its original die station before transferring another blank. It is also necessary for said transfer arms to have a dwell interval in order to "wait" for the ram to retreat from the dies. These transfer arms often reverse or turn the blank over 180.degree. during transfer. In any case, it is obvious that in addition to the long path of transfer the slow cutting speed and long stroke of the ram are also obstructions to high speed operation. Such devices may be seen in U.S. Pat. Nos. 3,069,917; 3,259,929; 3,717,890 and others.
Other transfer devices not employing transfer arms employ feeding plates or bars to transfer blanks directly from one die to the next. This transfer path is still very long and necessitates a dwell in the punching operation. These devices are seldom used today as it is not possible to effect the turning over of blanks which is necessary to insure proper facing. Such devices may be seen in U.S. Pat. Nos. 3,274,626; 3,533,115; 3,604,242 and others.
In the above said co-pending application the present inventor has eliminated all of the above defects by providing a feeding device wherein the distance of each transfer is at least one-fourth the distance of conventional devices which transfer directly from die to die, greatly reducing the length of the stroke of the main ram, while the mass of the transfer apparatus is also greatly decreased. Therefor it is possible to increase production rates by at least four times.
The primary object of the present invention is to provide an improvement on the transfer mechanism of the above said application so that suitable pressure is applied to each blank in the feed path and accurate positioning of each blank is assured.
Another object of the present invention is to provide an improvement on the transfer mechanism of said application so that misaligned nuts or other obstructions in the guide path will not cause damage to the transfer mechanism.
A further object of the present invention is to provide an improvement in the arrangement and coaction of the transfer mechanism and the guide path of said application so as to achieve the smoothest possible transfer operation and to provide easy and quick installation and set-up operations .